Control apparatus



Dec. 16, 1941. A. w. PLENSLER 2,266,710

CONTROL APPARATUS Filed July 2, 1940 3 Sheets-Sheet l Deco 16, 1941. A.- w. PLENSLER 2,266,710

CONTROL APPARATUS Filed July 2, 1940 3 Sheets-Sheet 5 3 P I 9; I 030 a? M H I l1 hi Dec. 16, 1941. A. w. PLENSLER 2,266,710

CONTROL APPARATUS Filed July 2, 1940 3 Sheets-Sheet 2 linear movement in the movable element of a Patented Dec. 16, 1941 PATENT OFFICE 2,266,710 common APPARATUS Alexander W. Plensler, Chicago, 111., assignor to Belmont Radio Corporation, Chicago, 11]., a

corporation of Illinois Application July 2, 1940, Serial No. 343,841

18 Claims.

This invention relates in general to control apparatus and more in particular to an automatic tuning system for a radio receiver. This invention relates to the structure of co-pending application, Serial No. 348,161, filed July 29, 1940, such application carrying the. claims dominating the control structure of the present application.

It is an object of this invention to provide an improved control system for controllable apparatus and particularly an improved tuning system for a radio receiver.

Another object of this invention is to provide automatic tuning apparatus-in which the station selector units are simply and easily adjusted for a particular tuning condition by a simple locking device, with the locking being accomplished as a result of a wedging action in the locking device.

A further object of this invention is to provide an improved automatic tuning system for a radio receiver in which linear movement of a selector unit is transmitted through simple effective mechanism to a linear moving element of an inductance tuning unit.

A feature of this invention is the provision of an adjustable element in a control unit, which is adjustable to a predetermined control position and then locked in such position in a very simple operation requiring the use of only one hand.

Another feature of this invention is the provision of tuning apparatusin which the station selector units include at least two relatively slidable members with an adjustable cam mounted upon one of the members, and being irictlonally locked in, and unlocked from, an adjusted position by the slidable movement of the other mem ber. Such other memberhas a finger knob portion which is grasped and pulled to unlock the, adjustable cam and is pushed to lock such cam and also to tune or select a station.

Yet another feature of this invention is the provision of tuning apparatus for a radio receiver having mechanism for changing rotary motion to linear motion, in which a linearly movable rack is in drivenengagement between a a rotary driving member and an idling pulley. The 45 driving member and pulley are so arranged and constructed so as to positively and smoothly drive the rack regardless of the magnitude and suddenness of the driving force applied on the rotary member.

Another feature of the invention is .the provision of simple, eilicient, mechanism for transmitting rotary movement in a control member to tuning inductance unit.

Further objects, features-and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawings in which:

5 Fig. 1 is a fragmentary plan view of the invention;

Fig. 2 is a sectional view as seen along the line 2-2 in Fig. 1;

Fig. 3 is a fragmentary elevational view illustrated similarly to Fig. 2 and showing a modified form of the rotary to linear motion changing mechanism;

Fig. 4 is an enlarged detailed sectional view of the idling pulley seen along the line 44 in Fig.

Fig. 5 is a sectional view of the idling pulley taken along the line 5-5 of Fig. 4 showing the parts thereof in changed position;

Fig. 6 is a detail elevational view of the selector unit illustrated in Figs. 1 and 3;

Fig. 7 is an enlarged sectional view as seen along the line 9-9 in Fig. 6;

Fig. 8 is an elevational view ofanother modifled form of a selector unit;

Fig. 9 is a fragmentary sectional view taken along the line ll-ll in Fig. 8;

Fig. 10 is an elevational view partly in section showing yet another modified form of a selector unit; and

compartment 26 by a bracing member 21 of plate form having extending portions 21' adapted chassis (not shown). Tuning from one frequency to another in the illustrated structure is accomplished'by permeability or inductance tuning. It is contemplated that the inductance coil units (not shown) be of the coil and core type and suitably positioned in the compartment 26, with the usual metal cores being in operative connection with a control bar 28, extending longitudinally of the tuning device. The control bar 0 28 is of substantially U-shape and is mounted near its opposite ends on connecting members 29 58 grally formed on the side walls 2i. The move- Fig. 11 is a reduced sectional view as seen along for supporting the tuning unit in the radio the radio receiving apparatus is to be used for 10 operation over two or more frequency bands. In the operation of frequency changing means utilizing movable cores or slugs, the tuning efllciency is dependent upon a simultaneous linear movement of the slugs and their return to simil6 lar relative positions for a predetermined control 4 position on their common control, such as the bar 28. An even and complete linear movement of the control bar 28 over its entire length is accomplished in the present lnvention by a pair of link assemblies 34, one of which is arranged neareach end of the bar 28. Since the link assemblies 34 are similar in construction only one of them will be referred to in the following description.

The mechanism 34 extends in both compartg5 ments 24 and 26 through apertures 36 formed in the partition plate 21, and operated to change the rotary motion of a treadle bar 31 or other suitable rotary control means to be later explained, into a linear motion for actuation of the 3 control bar 28. The treadle bar 31 is provided with a fixed arm 38, the free end of which is pivotally connected at 39 to one end 46 of a link member 4| of substantially hook shape. The

opposite end 42 of the member 4| is connected by a ball and socket joint 43 to the connecting member 29. End 42 is of substantially angular section with the leg portion 44 thereof being formed with a countersunk aperture for engaging a ball member 43 provided on the connecting member 29. A flat spring 46 secured at one end to the leg portion 44 maintains the ball and socket connection 43 in assembled engagement. The link 4| intermediate its ends 48 and 42 is pivotally connected at 41 to one end of a link 48,

' the opposite end of the link 48 being rotatably mounted on a shaft 49 which is supported in the end walls 2|. Assuming the treadle bar 31 to be rotated in a clockwise direction, as viewed in Fig.

2, link 38 moves end 40 of link 4| toward the 50 right, while the end 42 of link 4| moves with a substantially straight line movement toward the left, by virtue of the pivotal connection 41 and the travel of the lever end 40 and hence of the axis means 39 in an arcuate path which extends in the direction of linear movement of the connecting arms 29. In other words, the movement of the arm end 40 is such that it travels with a minimum of movement in a direction which is at substantially right angles to the axial or longitudinal plane of the connecting members 29. Since the connecting members 29 are connected to the link end 42 a linear movement is thus transmitted to the control bar 28 to operate the slugs in the coil inductance units.

The treadle bar is mounted on a shaft 45 which is rotatably supported at its opposite ends in the end walls 2|. Bar 31 is in one piece, of hollow construction, and of substantially V-shaped section, the adjacent angle or engaging portions 53 and 53' being supported by an integral slotted portion 54. The shaft 45 carries a gear segment 56 which meshes with a pinion 51 mounted at one end of a tuning shaft 58. Rotation of the units (not shown) to a given frequency through the link assemblies 34, in an obvious manner. Tuning indicating structure 6| mounted on the top cover 23 is connected with the shaft 58 5 through pulley assembly 62.

During automatic operation of the tuning apparatus rotation of the treadle bar 31 is accomplished by station selector units 68 which are linearly movable and slidably supported in the front panel 22 and in a bracket member 63. Each unit 66 as is best shown in Figs. 8 and 9, includes an actuator member 64 and an operating or carriage or slide member 66. The actuating member (Fig. 9) is provided with slot-like apertures 61 which are longitudinally spaced therein, the member 64 being mounted at these apertures on pins 68, which are secured to the carriage 66. A slidable movement of the actuating member 64 relative to the carriage 66 is thus obtained by means of the pin and slot connection therebetween. A push button or knob-like means 69 is provided at one end of the member 64 for manipulating the unit 66. The opposite end 10 of the actuating member is bifurcated and of tapered or wedge form and is arranged for insertion between the carriage 66 and a looking or rockable member on lever 1| mounted on the carriage 66 to raise such member or lever and pivot it around a fulcrum at side fingers or portions 14, upset overthe carriage as shown in Fig. 9. Member 1| intermediate its ends 12 and 13 is formed with laterally extending side fingers 14, which are loosely positioned in corresponding apertures 16 formed in the carriage 66. Fingers 14 are bent toward each other with their free ends in abutting engagement, to form a strap through the apertures 16 for holding the locking piece 1| on the carriage member. Sufficient length of the fingers is provided so that the locking member is movable transversely and pivotally relative to the carriage. A finger 11 formed at the end 12 of the locking member extends through an aperture 18 in the carriage 66 and is positioned between the bifurcations on the actuating member to keep these parts in proper alignment; end 12 being normally frictionally engageable with the end 10 of the push rod 64.

The end 13 of the locking member is normally frictionally engageable with a cam or an adjustable member 19, which is pivotally supported on a pin 8| mounted in the carriage 66.' The axis of the pin 8| is in longitudinal alignment with the slotted connections 61-68 and hence with the longitudinal axis of the actuating member 64. Cam 19 is relatively narrow and of semicircular section having flat diameter portions 82 and 82' arranged on opposite sides of the pivot pin 8|. Abutments 83 formed at each end of the arcuate portion 84 serve to limit the pivotal movement of the cam about pin 8| by engagement with the end 13 of the locking member which is of arcuate shape (Fig. 8) corresponding to the contour of the cam '19. End 13, as is shown in Fig. 9, is further of tapered or wedge form, the locking member being separated from the carriage 66 a distance suflicient to permit the end 13 to ride on the cam side away from the carriage. Although the member 1| acts to limit the angular movement of the cam 19 its principal function is in looking the cam in an adjusted position.

As indicated in Figs. 8 and 9 the selector unit 68 is shown in its normal operating arrangement with the cam 19 frictionally locked in an adjusted position by the locking member 1|. The

shaft 58 by turning knob 59 tunes the condenser end 10 of the actuator member or push rod 5:.

riage 66, which wedging action rocks or pivots the member end 13 into frictional engagement with the cam; the cam being firmly locked between the carriage and the locking member II. It is apparent that the greater the force exerted longitudinally of the push rod the greater will be the frictional locking pressure. The locking action of the member Il may be facilitated by slightly-bowing the member II; as shown in Fig. 9, to direct the pressure effected at the end 13 by the wedging action at the end 12 .more fully against the cam 19. On movement of the push rod end out of its wedged position between the member II and the carriage the cam 13 is entirely released of its frictional engagement with "m retracted from its wedged position between the member II and carriage 66, whereby to release such members and the cam 19"from their fric-' tionally' locked positions. This is accomplished by pulling on the knob 69. The treadle bar 31 ual pressure on the push rod 64 at the knob 69,

the member ll so as to be freely rotatable about the pin iii. The unit 60 is thus readily conditioned to be set to a predetermined tuned position; with the cam 19 being simply locked in-a particular adjusted position by the wedging action of the actuator 64 as will be later fully explained.

The normal operation of the selector unit in providing for the turning of the treadle bar 31 I and hence for the adjustment of the inductance coil units (not shown) to a predetermined tun-' ing position is best understood from Fig. 2; the, cam 19, actuator or push rod 64 and carriage 66 being in their frictionally locked positions. As indicated in Fig. 2 the'cam I9 and bar 31 are shown with the corresponding engaging portions 53 and 82 closer together than the engaging por-.

tions 53' and 82'. Thus on actuation of the unit, by pushing inwardly on the finger knob 69, the portions 53 and 82 are first brought into engagement, the continued linear movement of the unit 60 turning the treadie bar in a counterclockwise direction until the portions 53' and 82 are engaged. This engagement of both pairs of corresponding portions .53 and 82, and 53' and 82', represents the home or tuned position of the unit.

On rotation of the treadie bar 31 the link means or mechanism 34 operates to move the control bar 28, in the manner hereinabove fully described, to actuate the tuning cores or slugs connected thereto. The radio receiver is thus automatically tuned to the station identified by the particular selector unit 60.

The selector unit, after release of the knob 69, is returned to its idle position by the action of a coil spring 84 which is mounted abouta finger 86 on the carriage 66 and arranged in compression thereon between the carriage projection 81 and bracket 5 The bumper 88 on the panel 22 serves to cushion the return action of the unit. The above described operation of the unit is similar for any relative positioning of the bar 31 and cam 19, the engagement of the corresponding engaging portions of the bar and the cam nearest together at the start of unit actuation serving to faces will vary inaccordance with the particular frequency being tuned in with the device.

In the adjustment of the cam 19 to set it to a predetermined angular tuning position, the station selector 60 is arranged with the actuator end frictional engagement of friction washers F supported on the pins 68, with the rod 64 is suflicient to provide for aconcurrent linear travel of both the push-rod 64 and carriage 66 against the pressure of the spring. 84. The friction washers engagement also prevents the push rod 54 from moving far enough relative to the member H to move the latter into locking engagement with the cam so that the camcontinues to'be freely rotatable on itspivot pin 8|. On engagement of the bar and cam, engaging portions nearest together the cam 19 is rotated until both pairs of corresponding engaging portions are in engagement. The bar 31 meanwhile remains immovable and in the tuning position obtained by manipulation of the knob 53 as above described. In this position the carriage 66 is positively stopped due -to the fact the axis of the treadle bar andthe longitudinal axis of the push vrod 64 are in the same horizontal plane, so that the continued application of pressure on the push rod 64 effects a linear movement only of the push rod relative to the carriage. This movement of the push rod overcomes the friction of the washers F on the rod and urges the end 10 into its wedged position between the carriage 66 and locking member, whereby to increase the frictional pressure between the member end I3 and the cam .19. This frictionally locks the cam, carriage and push rod in a relatively fixed position, with the cam 19 being adjusted to the particular tuning position of the bar 31 as set by the operation of the tuning knob 59. During this actuation of the unit 60 the tuning knob 59, remainsuntouched and the radio operator need only use one hand in all of the manipulations of the selector unit 60 described, with the inductance units, .the treadle. and control bars and their connecting mechanism supplying all of the necessary inertia to the adjusting forces to make the desired adjustments possible.

On release of the pushv rod 64 the selector unit 60 in'its contracted position with the push rod end 10 in its wedged position, is returned to its starting or idle position by the return spring 84.

Later actuationof the unit will thus rotate the I bar 31 from any position which it might have to a position corresponding with the angular adjustment of the cam 19 to tune in a desired predetermined station. Release of the cam 19 to permit angular adjustment'for setting to a different station or control position is thus obtained by mere- 1y pulling thepush rod 54 in a direction toward the right, as viewed in Fig. 2, away from the treadle bar 31. The engagement of the abutments 83 on the cam 19 with the end 13 of the locking member H limits the angular rotation of the cam relative to the locking member to prevent the cam from rotating into a position which would prevent a full surface engagement between the open cam surface and the end 13 of the locking member. The shoulders 83 are spaced a distance apart to permit an angular rotation of the -cam which is slightly greater than the normal angular rotation of the treadle bar for covering the complete tuning range of the frequency changing means.

The tuning apparatus illustrated in Fig. 3 is substantially similar in many respects to that shown in Fig. 1 and similar numerals of reference, therefore, shall be used to designate similar parts. Each link assembly 34 includes a link 89 which is pivotally connected at its end 9I to the of the tuning apparatus as above described in connection with the assemblies 34 of Fig. 1. Gear 93 is formed with a peripheral groove of substantially semi-spherical shape having teeth thereon for engaging corresponding teeth formed on a non-rotatable but linearly movable rack member 96. The rack 96 is of circular section and is connected at 91 to a connecting member 29. The rack is supported for linear movement transversely of the tuning unit by the onnection 91 and by its arrangement between the gear 93 and an idling pulley 98 (Figs. 4 and 5), which is rotatably supported on a pin 99 mounted in the end walls 2 I.

The pulley unit 98 is comprised of mating face I portions IOI of substantially dish shape, the side walls I02 of which extend outwardly from the rack 98 so that the rack is in engagement with the convex face portions of such outwardly extending side walls. It has been found that engagement of a. convex portion of the pulley faces' IOI provides for a smoother and more even contacting surface with the rack 96 than a portion of concave or like contour. Pulley faces IOI are mounted on a hub portion I93 which is provided with annular end or retaining flanges I04 for springs I06. Each spring I06 is arranged in compression between a pulley face IN and a retaining flange I04 so that the face portions are separably movable in a direction axially of the pin. Although the pressure of the springs I09 acts in a direction axially of the pin shaft 99, the curvature of the side plates or walls I02 is such that a portion of the spring pressure is applied at the side walls in a direction toward the center of the rack 96. The spring pressure thus acts toward the center of the idling unit or pulley 99 to hold the faces IOI' in a separable but operable assembly, and further by virtue of the structure of plates I02 acts to force the rack 96 into engagement with the segmental gear 93.

A washer or non-yieldable member I01 is mounted on the hub member I03 between the pulley side plates IN. The washer is of a diameter such that when the rack 96 and gear 93 are in full mesh engagement, as indicated in Fig. 4, the distance between the lines AA is less than about one half the distance shown as B-B, between the root diameters of the rack 96 and segmental gear 93. The rack, therefore. cannot be pulled out of toothed engagement with the gear 93. In other words, separation of the pulley side plates IOI on passage of the rack downwardly therebetween, as viewed in Fig. 4, will take place until the rack engages the peripheral edge of the washer I01. Since the washer is on a fixed pin shaft 99 and hence unyieldable the rack cannot be skidded or slipped axially or the gear 93 cannot be slipped with reference 35 illustrated. in Figs. 10 and 11.

rack and washer I 01 is shown in Fig. 5, the engagement of the rack and gear 93 being clearly indicated for this extreme operating position of the rack.

5 In the manual actuation of the selector units 60 it sometimes occurs that the actuation occurs rather suddenly so that the selector mechanism is subjected to Jerks or relatively high speed operation. This sudden heavy force applied on 10 the gear 93, through the treadle bar 31 and link assembly 34' tends to push the rack 96 out of its meshed engagement with the gear 93 by virtue of the pressure reactions between the engaged teeth. The rack 96 is thus urged between the pulley face plates IN to relieve frictional pressure between the rack 96 and gear 93, whereby to prevent a binding or locking of such parts. At no time, however, will the rack slip out of engagement with the gear 93, because of the stopping action of the washer I01, as above explained. The structure of the idling pulley 98 thus provides for a minimum driving friction between the gear 93 and rack 19 at all times, whereby the tuning apparatus may be positively and eiTlciently operated with a minimum of. ef-

3 is similar to that above described in connection with Figs. 1 and 2 and further explanation of such operation is therefore believed to be unnecessary.

A further modified form of selector unit is The unit I60 includes an operating or carriage member I24 and an actuating member I'26. The member I26 is formed with longitudinally spaced slots I21 and is slidably mounted at these slots on pins 40 I28 carried by carriage member I24. Actuating member I26 is spaced from the member I24 by spacers I29 so that the tapered end I3I will engage the outer rear edge of the adjustable element 19 which is pivotally supported on the carriage member I24 and is normally frictionally engageable therewith. With the actuating member I26 urged into frictional engagement with the adjustable element 19, which position is indicated in Figs. 10 and 11, actuation of the se- 5 lector unit I60 operates to move the treadle bar I24 in abutting engagement with the front panel portion 22 as shown in Fig. 10, the actuating member I24 is pulled to the left to release the cam 19 from its wedged position against the carriage I24 so that it is freely rotatable, and in a condition to be adjusted toa position in correspondence with the predetermined control position of the treadle member 31. A friction washer F is mounted on each pin I28 to retain the push rod or actuating member I26 out of wedging engagement with the cam 19 during the inward movement of the push rod when it is in released position relative to the cam. Adjustment of the cam 19 to an adjusted position is believed to be obvious from the foregoing description so that further explanationthereof is believed to be unnecessary.

Yet another modified form of a selector unit is illustrated in Figs. 12 andvl3, the unit 260 including an operating or carriage member I32 and to the rack 96. This engaged position of the an actuating 0r nobi e member I33. The

unit v260 is slidably mounted in the bracket 93 and front panel 22 of the unit frame means 20 so as to be linearly movable therein. The carriage I32 is formed with a bumped out lip 'portion I 34 which is in longitudinal alignment with the pivotal support BI for theadjustable cam member 19. A slightly bowed spring member I38 is loosely carried on the carriage I32 between the lip portion I34 and the adjustable cam 19' and is normally frictionally engaged with the cam member and the actuating member I33, which has a recess I3I therein ofa form to be slipped over the end I38 of the carriage member. As viewedin Fig. 12 the'carriage I32 and actuating member I33 are, in their closed position with the spring I38 wedged between the lip, I34 and cam I9 to frictionally lock the element 19 in an adjusted position. Thus on movement of the selector unit 260 toward the left the engaging portions 53 and 82 on the treadle member 31 and cam I9, respectively, are engaged, with the continued movement of the selector unit moving the treadle member 31 in a clockwise direction until the corresponding portions 53 and 82' are also engaged, this position of the treadle bar 3! representing a predetermined control position thereof. a

Although the invention has been described with reference to preferred embodiments of the invention, it is to be understood that modifica-- tions and alterations thereof can be made which are within the full intended scope of the 'inven; tion as defined by the appended claims.

I claim: 4, 1. In control apparatus having rotary control means, the combination of frame means, means In setting the cam I9 in an adjusted tuning position, when the unit 260 is in the position indicated in Fig. 12, with the shoulders S of the carriage I32 abutting the panel 22', the knoblike member I33 is pulled outwardly to the right, as viewed in Fig. 12, moving linearly relative to the carriage I32. Upon engagement of the' lip or flange portion I39 on the member I33 with the frame wall NI, the spring I36 is entirely released from its frictional engagement with the adjustable element or cam I9, and the latter is then freely rotatable on the carriage I 3| Assuming the treadle 31 to be in a desired tuning position, the member I33 is moved to the left toward the treadle 31. Because of the loose mounting of the spring I36 on the carriage I32, moving or sliding of the member I33 onto the carriage end I38 acts first to seat the spring firmly against the cam I9 before the exertion of any pressure resulting from the wedging of the spring in the recess I31. The seating of the spring with the cam 19 is facilitated by forming 1 their engaging portions of like contour. This initial spring pressure is sufiicient tohave the carriage I32 move concurrently with the actuating member I 33 on continued movement thereof but does not prevent the cam 19 from being freely rotatable on the pin shaft 80. The-cam i9 is thus free to be turned into an engaged position with its engaging portions 82 and 82' in engagement with the corresponding portions 53 and 53' on the treadle 31. The continued movement of the member I33, after this engagement has been established, causes the member 833 to slide over the carriage end I32. This action of the actuating member provides for the exertion of -a spring pressure both longitudinally and laterally of the spring,the longitudinal displacement being less than its lateral displacement so that the spring acts as a toggle to apply a magnified loading pressure on the cam I9, whereby to frictionally lock the cam "I9 in the angular position corresponding to the desired predetermined control position of the treadle 31. The actuating member I33 may be provided in Bakelite or like'material with a metal insert I42 in the recess I37 thereof in slidable engagement with the spring member I36.

on said frame means for rotating said control means including a movable carriage unit, an actuator unit, with. said carriage unit having a portion upporting said actuator unit thereon for slidable movement relative thereto, and an adjustable element mounted on said carriage unit, with one of said units having a portion frictionally engaging said adjustable 'element'to lock the same in adjusted position, and with said carriage unit having a stop portion for engagement with the frame means to hold said carriage unit stationary while pulling out the actuator unit for slidable movement relative to the carriage unit to remove said friction portion sufficiently from locking engagement with said adjustable element to permit adjusting movement of said element.

2. In control apparatus having movable control means, the means for moving said control means to apredetermined control position including a linearly slidable actuating member, an operating member, means connect-ing-saidtwo members together for relative linear slidable movement, a driving member adjustably supported on said operating member, and meanson said operating member for releasably locking said driving member in an adjusted position and said two members v .a second unit supported upon said first unit for longitudinal but non-rotatable movement relative thereto, adjustable means on said first unit, and retaining means for said adjustable means including a substantially elongated member supported upon said first unit and operatively connected with said adjustable member for retaining the same, said member having a portion operatively connected with said second unit and movable laterally with reference to said first unit upon longitudinal non-rotatable movement of said second unit relative to said first unit, with said second unit being non-rotatably pushable portion having a finger-hold thereon, means supporting said second portion on said first portion for non-rotary but longitudinal movement of said second portion with reference to said first portion, and movable locking means supported on said first portion and operatively connecting said element and said second portion, with said locking means adapted to be selectively tipped into or out of frictional locking engagement with said element upon longitudinal but non-rotary movement of said second portion by a corresponding selective push or pull at said fingerhold thereon when said control unit is stopped at an end of its operating path.

5. In control apparatus having movable control means, means for moving said control means to a predetermined control position, including an operating unit, means slidably supporting said operating unit for movement to an operating and to a rest position, an adjustable member adjustably supported on said operating unit, finger operated means in slidable engagement with said operating unit and longitudinally movable relative thereto, means irictionally holding said adjustable member in an adjusted position, and means movably supporting said holding means on said operating unit in a plane substantially parallel to the plane of said operating unit but permitting a tipping movement of said holding means in a direction substantially laterally 01' said operating unit, said holding means being operatively engageable with said adjustable member and finger operated means, said finger operated means being slidably but non-rotatably pushable toward said movable control means when said operating unit is in said operating position to tip said holding means into frictional engagement with said adjustable member, and said finger operated means being slidably but non-rotatably pullable away from said movable control means when said operating unit is in said rest position to i'rictionally release said holding means and adjustable member.

6. In radio receiving apparatus including rotary tuning means, means for rotating said tuning means including a station selector unit having a carriage, an actuating member on said carriage, means connecting said actuating member and carriage to provide for an independent movement of said actuating member between two operating positions, a driving element adjustably supported on said carriage, and means pivotally supported on said carriage and normally frictionally engageable with said driving element and actuating member, with one portion of said actuating member being movable to a wedged position between said pivotal means and carriage, said one portion on movement of said actuating member to one of said two operating positions acting as a wedge to move said pivotal means into frictional engagement with said driving element to hold said driving element in an adjusted position.

position, and means movably' supporting said holding means on said carriage member .ior tipping movement relative thereto, with a portion of said adjustable member being arranged beadjustable member, said finger operated means i being longitudinally but non-rotatably pushable in one direction relative to said carriage member when said carriage member is in one of said operating positions to tip the one end of said holding means into its friction applying position, and -said finger operated means being longitudinally but non-rotatably movable in an opposite direction relative to said carriage member when said carriage member is in the other of its operating positions to provide for the release of said adjustable member from its frictionally locked position.

8. In control apparatus having movable control means, selector means for moving said control means to a predetermined control position including an operating unit, an actuating unit, means including a portion of said operating unit for supporting said actuating unit on said operating unit for slidable and substantially linear movement relative thereto, an adjustable element adjustably supported on said operating unit and engageable with said control means, means movably supported on said operating unit intermediate said actuating unit and adjustable element, said intermediate means having one portion thereof irictionally' engageable with said adjustable element to lock the same in an adjusted position, and said actuating member having a side portion thereof slidably engageable with a second portion of said intermediate means, said side portion on slidable substantially linear but non-rotatable movement of said actuating unit toward said control means relative to said-operating unit slidably engaging the second portion of said intermediate means to move the first portion thereof laterally oi the direction or movement of the actuating unit and into a frictional locking position with said adjustable element.

9. In control apparatus having movable control means, selector means for moving said control means to a predetermined control position including a carriage, a linearly movable actuating member supported on said carriage and slidable relative thereto, and an adjustable element supported on said carriage, said actuating memher having a tapered portion at one end riding on said element in one relative position of the carriage and actuating member to frictionally engage said element, with linear sliding movement of said actuating member to said one position frictionally locking said element in an adjusted position. a

10. In radio receiving apparatus including rotary tuning means, means for rotating said tuning means including a linearly actuated station selector unit having a carriage member, said carriage having a longitudinally extending portion, an adjustable driving element pivotally supported at one end 01 said portion, with said portion having a projecting lip in substantial alignment with the pivotal support of said element, a fiat spring positioned between said element and projecting lip, said spring being convexly bowed outwardly from said carriage member, and a knob member having a cavity in one endthereof for receiving the other end of said longitudinal portion, said knob member being slidably movable in'one direction relative to said carriage member to clamp said spring within said cavity to frictionally lock said driving element in an adjusted position, with movement thereof in an opposite direction releasing said spring from its clamped position.

11. In control apparatus, control means movable in a longitudinal direction of travel and including a first unit, a second unit supported upon said first unit for longitudinal but non-rotatable movement relative thereto, adjustable means mounted upon said first unit, said first unit having a stop portion thereon to stop the longitudinal movement of the control means at one end of its travel in the control apparatus, one of said units having a portion operatively connected with the other unit and with the adjustable means when said adjustable means is in a fixed position to releasably retain said means in said fixed position, and said one unit portion being movable out of said retaining position upon longitudinal non-rotatable movement of said second unit relative to said first unitat one end of the travel of the control means when said stop portion is in a stop position and holding said first unit stationary.

12. In radio tuning apparatus having rotary control means, linearly actuated selector means for rotating said control means including an operating unit having a pair of longitudinally aligned extensions, an adjustable element pivotally supported on one of said extensions and operatively engageable with said control means, said other extension having a projection thereon in substantial longitudinal alignment with the pivotal support for said element, means for locking said element in an adjusted position, and means including an actuating unit movably supporting said locking means on said operating unit between said element and projection, said actuating unit having a cavity in one end thereof for slidably receiving said other extension and a portion of said locking means, said actuating unit on sliding movement thereof in one direction engaging said first portion of the locking means and moving a second portion of said locking means against said element to frictionally lock said element in an adjusted position and said actuating and operating units for concurrent movement.

13. In control mechanism having controllable means, a selector-slide-structure carrying an adjustable setting device for operating the controllable means, a manually pull-push and nonrotatable operable member mounted on said slide structure, said member having a clamping portion at one end to clamp said setting device and having finger-hold means at the other end, and said member being non-rotatably pullable away from said setting device'while the structure is in a stop position to release said setting device.

14. In a tuning structure for a radio set, a

push-button slidable structure carrying an adjustable setting device, the said structure having two parts non-rotatably slidably interconnected, a lever connected with one part adapted to be placed in locking engagement with the setting device, and a raising portion on the other part cooperating with said lever for forcing said lever into said locking engagement.

15. In a tuning structure for a radio set, a push-button slidable structure carrying an adjustable setting device, said device being adapted to be held in any adjusted position by a levertype clamp, a lever-type clamp on said slidable structure, and said slidable structure having means including a push-button for placing the clamp in holding position upon push of the pushbutton and for releasing the clamp from its holding position for resetting said device by an outward pull on the push-button.

16. In a tuning structure for a radio set, a push-button slidable structure carrying an adjustable setting device, said device being held in any adjusted position by a lever-type clamp, said slidable structure including a lever-type clamp, said slidable structure having means operatively connected with said clamp and having a pushbutton thereon with the clamp being released from its locking position for resetting said device by an outward pull on the push-button, the lever clamp being moved to clamping position by a push on the button harder than that required for a normal operation of the slidable structure and the setting device thereon to preset the setting device.

17. A push-button slidable tuning structure for use in a radio set including a slide member, an actuator member movably carried on the slide, a setting device carried by the slide, a lever pivotally carried on the slide and including a part for engaging the setting device and another part to be engaged bya part on the actuator to move the lever to lockingly engage the setting device, said lever including an upset portion retaining the said lever on said slide, with said portion being of such dimension as to space said lever from said slide member for entry of said part of said actuator thereunder, and push means carried on the outer end of the actuator for manipulating it.

18. In a tuning device for a radio set, a tuning slide structure having a main slide member and I carrying an adjustable setting device pivotally mounted on one side of the main slide member, said structure carrying a lever arranged to apply pressure to clamp said setting device against said main slide member, and slidable butnonrotatable means carried on said slide structure to operate said lever to release or clamp the setting device.

ALEXANDER W. PLENSLER. 

